CVE-2026-123527: Auth Bypass (CVSS 5.4)

Description

Vikunja from 2.4.0 before 2.7.1 contains an authorization bypass vulnerability that allows token holders to perform unintended operations due to colliding v1 and v2 API token permission keys. Attackers with a token scoped to read project backgrounds can delete them via the v2 DELETE background route, and bucket create-only tokens can update existing buckets.

Is your site exposed to CVE-2026-123527?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

5.4

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

EPSS — Exploit Prediction

0.0024

Probability of exploitation

0.15%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-863 Incorrect Authorization

References

Other References

https://github.com/go-vikunja/vikunja/security/advisories/GHSA-j5v7-qcwp-5g32 https://www.vulncheck.com/advisories/vikunja-2.4.0-before-2.7.1-api-token-scope-collision-authorization-bypass https://github.com/go-vikunja/vikunja/security/advisories/GHSA-j5v7-qcwp-5g32

Frequently Asked Questions

What is CVE-2026-123527? +

Vikunja from 2.4.0 before 2.7.1 contains an authorization bypass vulnerability that allows token holders to perform unintended operations due to colliding v1 and v2 API token permission keys. Attackers with a token scoped to read project backgrounds can delete them via the v2 DELETE background route, and bucket create-only tokens can update existing buckets. It has a CVSS v3.1 base score of 5.4 (MEDIUM).

How severe is CVE-2026-123527? +

CVE-2026-123527 has a CVSS v3.1 score of 5.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0024, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-123527? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-84355

Incorrect authorization in Navigation in Google Chrome prior to 152.0.7977.75 allowed a remote attacker who had compromised the renderer process …

CVE-2026-65601

Traefik versions 3.7.0 through 3.7.6 contain a namespace confusion vulnerability in the Kubernetes Gateway API provider. When resolving HTTPRoute.spec.rules[].backendRefs[].filters[].extensionRef, Traefik …

CVE-2026-50008

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. From version …

CVE-2026-15829

A SQL injection (CWE-89) and security boundary bypass (CWE-863) vulnerability exists in the prebuilt BigQuery forecasting tool (bigquery-forecast) of googleapis/mcp-toolbox. …

CVE-2026-42571

Pelican is a platform for creating data federations. From versions 7.21.0 to before 7.21.5, 7.22.0 to before 7.22.3, 7.23.0 to …

CVE-2026-42137

Kirby is an open-source content management system. Prior to versions 4.9.0 and 5.4.0, `pages.access/list` and `files.access/list` permissions are not consistently …